Some [4,3-a]-s-triazolo-1,4-benzodiazepines, especially those substituted in the 6-position by phenyl, have been mentioned as having a pronounced effect on the central nervous system. Thus J-B Hester et al. (J. of Med. Chem. 1971, 1078-1081) have described a chemical series closely related to the substituted 5-phenyl-1,4-benzodiazepines previously studied by G. A. Archer and L. H. Sternbach (J. Org. Chem. 29, 231, 1964).